Simply measure the inside WIDTH of your cabinet and subtract 1/4" to get your ordered width.

The Add-A-Shelf is always 18 inches DEEP which will accommodate the installation of any Pullout Shelf that you order for it.

If you have a "Half Shelf" in the back of your cabinet and want to install an Add-A-Shelf in front of it, you can reduce the depth of the Add-A-Shelf so that it will fit in front of the "Half Shelf"and extend up to the front of your cabinet. If you want to reduce the depth for your Add-A-Shelf, click the Depth Box and enter the depth from the front of your Half Shelf to the front of the cabinet (inside edge) less 1/4".

The Add-A-Shelf is a great solution to a common problem that is easy to install and reasonably priced!